/* ── File Manager Module ── */
window.FilesModule = {
    currentPath: '',
    contextTarget: null,
    toDelete: null,
    pickerMode: false,
    pickerCallback: null,

    init: function() {
        var self = this;
        var params = new URLSearchParams(window.location.search);
        if (params.get('picker') === '1') {
            self.pickerMode = true;
            self.pickerMode = params.get('mode') || 'dir';
            self.pickerCallback = params.get('cb') || null;
        }
        window.addEventListener('message', function(e) {
            try {
                var d = JSON.parse(e.data);
                if (d.action === 'fm-picker-open') {
                    self.pickerMode = true;
                    self.pickerMode = d.mode || 'dir';
                    self.pickerCallback = d.callback_id || null;
                    self.refresh();
                }
            } catch(ex) {}
        });

        // Path input: Enter to jump
        var input = document.getElementById('fm-path-input');
        input.onkeydown = function(e) {
            if (e.key === 'Enter') {
                var p = input.value.trim();
                if (p) self._jumpTo(p);
            }
        };

        self.refresh();
    },

    /* ── API helpers ── */
    _apiBase: '',
    _apiUrl: function(path) {
        // Use explicit base if set (standalone/iframe mode), otherwise relative
        if (this._apiBase) return this._apiBase + '/api/files' + path;
        return './api/files' + path;
    },
    _api: function(url, opts) {
        opts = opts || {};
        opts.credentials = 'include';
        return fetch(url, opts).then(function(r) {
            if (!r.ok) throw new Error(r.status + ' ' + r.statusText);
            return r.json();
        });
    },
    _get: function(url) { return this._api(this._apiUrl(url)); },
    _post: function(url, body) {
        return this._api(this._apiUrl(url), {method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify(body)});
    },

    /* ── Jump to path (with existence check) ── */
    _jumpTo: function(path) {
        var self = this;
        // Probe: try to list the target path
        this._get('/info?path=' + encodeURIComponent(path))
            .then(function(info) {
                if (info.error) { self._pathError(info.error); return; }
                if (info.is_dir) {
                    self.currentPath = info.path;
                    self.refresh();
                } else {
                    self._pathError('路径是文件，不是目录');
                }
            }).catch(function(e) {
                self._pathError('目录不存在或无权限访问: ' + path);
            });
    },

    _pathError: function(msg) {
        var list = document.getElementById('fm-list');
        list.innerHTML = '<div style="text-align:center;color:var(--error);padding:40px">' +
            '⚠ ' + this._esc(msg) + '</div>';
        // Still update the input and breadcrumb to show what was attempted
        document.getElementById('fm-breadcrumb').innerHTML =
            '<span class="fm-crumb" style="color:var(--error)">' + this._esc(msg) + '</span>';
    },

    navigate: function(path) {
        this.currentPath = path || '';
        this.refresh();
    },

    refresh: function() {
        var self = this;
        var showHidden = document.getElementById('fm-hidden')?.checked ? '1' : '0';
        self._get('/list?path=' + encodeURIComponent(self.currentPath) + '&show_hidden=' + showHidden)
            .then(function(d) {
                self._render(d);
            }).catch(function(e) {
                document.getElementById('fm-list').innerHTML =
                    '<div style="text-align:center;color:var(--error);padding:40px">加载失败: ' + self._esc(e.message) + '</div>';
            });
    },

    /* ── Render ── */
    _render: function(d) {
        var self = this;

        // Update editable path input
        var input = document.getElementById('fm-path-input');
        input.value = d.current || '';

        // Breadcrumbs (logical path)
        var bc = document.getElementById('fm-breadcrumb');
        var html = self._buildBreadcrumbHTML(d.breadcrumbs);
        // Resolved breadcrumbs — show as second row when symlink redirect
        if (d.resolved_breadcrumbs) {
            html += '<div class="fm-resolved-crumbs">' +
                '<span class="fm-crumb-sep" style="color:var(--primary)">↳</span>' +
                self._buildBreadcrumbHTML(d.resolved_breadcrumbs) + '</div>';
        }
        bc.innerHTML = html;
        bc.querySelectorAll('.fm-crumb').forEach(function(el) {
            el.onclick = function() { self.navigate(this.dataset.path); };
        });

        // File list
        var list = document.getElementById('fm-list');
        var rows = '';

        // ".." row for parent (unless at filesystem root)
        if (d.parent && d.parent !== d.current) {
            rows += '<div class="fm-row fm-dir fm-parent" data-path="' + self._escAttr(d.parent) + '" data-is-dir="1">' +
                '<span class="fm-icon">📂</span>' +
                '<span class="fm-name" style="font-weight:600">..</span>' +
                '<span class="fm-size"></span>' +
                '<span class="fm-date"></span>' +
                '</div>';
        }

        if (d.items && d.items.length) {
            d.items.forEach(function(item) {
                if (item.broken) {
                    // Broken symlink or unreadable entry — show as disabled
                    rows += '<div class="fm-row fm-broken" data-path="">' +
                        '<span class="fm-icon">❓</span>' +
                        '<span class="fm-name" style="color:var(--error)" title="损坏的链接或无法访问">' + self._esc(item.name) + '</span>' +
                        '<span class="fm-size">—</span>' +
                        '<span class="fm-date">—</span></div>';
                    return;
                }
                var icon = item.is_dir ? '📁' : FilesModule._fileIcon(item.ext);
                var sizeStr = item.is_dir ? '—' : FilesModule._fmtSize(item.size);
                rows += '<div class="fm-row' + (item.is_dir ? ' fm-dir' : '') +
                    '" data-path="' + self._escAttr(item.path) +
                    '" data-is-dir="' + (item.is_dir?'1':'0') + '">' +
                    '<span class="fm-icon">' + icon + '</span>' +
                    '<span class="fm-name">' + self._esc(item.name) + '</span>' +
                    '<span class="fm-size">' + sizeStr + '</span>' +
                    '<span class="fm-date">' + (item.mtime_str || '') + '</span>' +
                    '</div>';
            });
        }
        if (!rows) {
            list.innerHTML = '<div style="text-align:center;color:var(--text-dim);padding:40px">空目录</div>';
        } else {
            list.innerHTML = rows;
        }

        // Row click handlers
        list.querySelectorAll('.fm-row').forEach(function(row) {
            row.onclick = function(e) {
                var p = this.dataset.path;
                var isDir = this.dataset.isDir === '1';
                if (isDir) {
                    self.navigate(p);
                } else if (self.pickerMode) {
                    self._pickResult(p);
                }
            };
            row.oncontextmenu = function(e) {
                e.preventDefault();
                self._showContext(e, {
                    path: this.dataset.path,
                    isDir: this.dataset.isDir === '1',
                    name: this.querySelector('.fm-name').textContent
                });
            };
        });

        // Close context on outside click
        document.onclick = function() {
            document.getElementById('fm-context').style.display = 'none';
        };

        // Picker banner — at bottom
        if (self.pickerMode) {
            var banner = document.getElementById('fm-picker-banner');
            if (!banner) {
                banner = document.createElement('div');
                banner.id = 'fm-picker-banner';
                banner.innerHTML = '<div style="display:flex;align-items:center;gap:8px;padding:6px 12px;background:var(--primary-container);color:var(--md-sys-color-on-primary-container);border-radius:var(--shape-xs);font-size:.82rem">' +
                    '<span>📂 选择' + (self.pickerMode === 'file' ? '文件' : '目录') + '模式</span>' +
                    '<button class="btn btn-sm btn-filled" onclick="FilesModule._pickResult(FilesModule.currentPath)" style="margin-left:auto">选择当前目录</button>' +
                    '<button class="btn btn-sm btn-outlined" onclick="FilesModule._cancelPicker()">取消</button>' +
                    '</div>';
                list.parentNode.appendChild(banner);
                list.style.flex = '';
                banner.style.marginTop = 'auto';
                banner.style.paddingBottom = '0';
            } else {
                banner.style.display = 'block';
            }
        } else {
            var oldBanner = document.getElementById('fm-picker-banner');
            if (oldBanner) oldBanner.style.display = 'none';
        }
    },

    /* ── Picker ── */
    _pickResult: function(path) {
        // In iframe (picker mode): post to parent, parent closes overlay
        if (window.parent !== window) {
            window.parent.postMessage(JSON.stringify({action:'fm-picked', path: path, callback_id: this.pickerCallback}), '*');
            return;
        }
        // Standalone clipboard fallback
        navigator.clipboard?.writeText(path);
        alert('已选择: ' + path);
        this.pickerMode = false;
        this.refresh();
    },
    _cancelPicker: function() {
        if (window.parent !== window) {
            window.parent.postMessage(JSON.stringify({action:'fm-picked', path: null, callback_id: this.pickerCallback}), '*');
            return;
        }
        this.pickerMode = false;
        this.refresh();
    },

    /* ── Create ── */
    createFile: function() {
        var self = this;
        var name = prompt('新建文件名:');
        if (!name) return;
        this._post('/touch', {path: this.currentPath, name: name})
            .then(function() { self.refresh(); })
            .catch(function(e) { alert('创建失败: ' + e.message); });
    },
    createDir: function() {
        var self = this;
        var name = prompt('新建文件夹名:');
        if (!name) return;
        this._post('/mkdir', {path: this.currentPath, name: name})
            .then(function() { self.refresh(); })
            .catch(function(e) { alert('创建失败: ' + e.message); });
    },
    upload: function(files) {
        var self = this;
        if (!files || !files.length) return;
        var form = new FormData();
        for (var i = 0; i < files.length; i++) form.append('file', files[i]);
        fetch(self._apiUrl('/upload?path=') + encodeURIComponent(self.currentPath), {method:'POST', credentials:'include', body:form})
            .then(function(r) { return r.json(); })
            .then(function(d) {
                if (d.ok) self.refresh();
                else alert('上传失败: ' + (d.error || 'unknown'));
            }).catch(function(e) { alert('上传失败: ' + e.message); });
    },

    /* ── Editor ── */
    openEditor: function(path, name) {
        var self = this;
        this._get('/read?path=' + encodeURIComponent(path))
            .then(function(d) {
                document.getElementById('fm-editor-title').textContent = '📝 ' + (name || d.name);
                document.getElementById('fm-editor-textarea').value = d.content;
                document.getElementById('fm-editor-textarea').dataset.path = path;
                document.getElementById('fm-editor').style.display = 'flex';
            }).catch(function(e) { alert('无法读取: ' + e.message); });
    },
    closeEditor: function() {
        document.getElementById('fm-editor').style.display = 'none';
    },
    saveFile: function() {
        var self = this;
        var ta = document.getElementById('fm-editor-textarea');
        this._post('/write', {path: ta.dataset.path, content: ta.value})
            .then(function() { self.closeEditor(); self.refresh(); })
            .catch(function(e) { alert('保存失败: ' + e.message); });
    },

    /* ── Context menu ── */
    _showContext: function(e, item) {
        this.contextTarget = item;
        var ctx = document.getElementById('fm-context');
        ctx.style.display = 'block';
        ctx.style.left = e.pageX + 'px';
        ctx.style.top = e.pageY + 'px';
        var items = ctx.querySelectorAll('.fm-context-item');
        items[2].style.display = item.isDir ? 'none' : 'block';
    },
    ctxDownload: function() {
        var t = this.contextTarget;
        if (t) window.open(FilesModule._apiUrl('/download?path=') + encodeURIComponent(t.path), '_blank');
        document.getElementById('fm-context').style.display = 'none';
    },
    ctxRename: function() {
        var self = this;
        var t = this.contextTarget;
        if (!t) return;
        var nn = prompt('新名称:', t.name);
        if (!nn || nn === t.name) return;
        this._post('/rename', {path: t.path, new_name: nn})
            .then(function() { self.refresh(); })
            .catch(function(e) { alert('重命名失败: ' + e.message); });
        document.getElementById('fm-context').style.display = 'none';
    },
    ctxEdit: function() {
        var t = this.contextTarget;
        if (t && !t.isDir) this.openEditor(t.path, t.name);
        document.getElementById('fm-context').style.display = 'none';
    },
    ctxDelete: function() {
        var t = this.contextTarget;
        if (!t) return;
        this.toDelete = t;
        document.getElementById('fm-dialog-msg').textContent = '确认删除 "' + t.name + '"？此操作不可撤销。';
        document.getElementById('fm-dialog').style.display = 'flex';
        document.getElementById('fm-context').style.display = 'none';
    },
    confirmDelete: function() {
        var self = this;
        if (!this.toDelete) return;
        this._post('/delete', {path: this.toDelete.path})
            .then(function() { self.toDelete = null; self.closeDialog(); self.refresh(); })
            .catch(function(e) { alert('删除失败: ' + e.message); });
    },
    closeDialog: function() {
        document.getElementById('fm-dialog').style.display = 'none';
        this.toDelete = null;
    },

    /* ── Helpers ── */
    _buildBreadcrumbHTML: function(crumbs) {
        if (!crumbs || !crumbs.length) return '';
        var h = '';
        for (var i = 0; i < crumbs.length; i++) {
            var c = crumbs[i];
            h += '<span class="fm-crumb" data-path="' + this._escAttr(c.path || '') + '">' + this._esc(c.label) + '</span>';
            if (i < crumbs.length - 1) h += '<span class="fm-crumb-sep">▸</span>';
        }
        return h;
    },
    _esc: function(s) {
        return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
    },
    _escAttr: function(s) {
        return String(s).replace(/&/g,'&amp;').replace(/"/g,'&quot;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
    },
    _fmtSize: function(bytes) {
        if (bytes === null || bytes === undefined) return '—';
        if (bytes < 1024) return bytes + ' B';
        if (bytes < 1048576) return (bytes / 1024).toFixed(1) + ' KB';
        if (bytes < 1073741824) return (bytes / 1048576).toFixed(1) + ' MB';
        return (bytes / 1073741824).toFixed(2) + ' GB';
    },
    _fileIcon: function(ext) {
        var map = {
            '.py':'🐍','.js':'📜','.ts':'📘','.html':'🌐','.css':'🎨',
            '.json':'📋','.yaml':'⚙','.yml':'⚙','.md':'📝','.txt':'📄',
            '.log':'📊','.sh':'💻','.bat':'💻','.xml':'📰','.toml':'⚙',
            '.cfg':'⚙','.ini':'⚙','.conf':'⚙','.sql':'🗄','.csv':'📊',
            '.zip':'📦','.tar':'📦','.gz':'📦','.7z':'📦',
            '.png':'🖼','.jpg':'🖼','.jpeg':'🖼','.gif':'🖼','.svg':'🖼','.ico':'🖼',
            '.mp3':'🎵','.wav':'🎵','.ogg':'🎵','.mp4':'🎬','.avi':'🎬',
            '.pdf':'📕','.doc':'📃','.docx':'📃','.xls':'📊','.xlsx':'📊',
            '.c':'⚡','.h':'⚡','.cpp':'⚡','.java':'☕','.rs':'🦀','.go':'🔵',
        };
        return map[ext] || '📄';
    },

    destroy: function() {
        document.getElementById('fm-context').style.display = 'none';
        document.getElementById('fm-dialog').style.display = 'none';
        document.getElementById('fm-editor').style.display = 'none';
    }
};